Centrifugal switch



1946' J. w. BUSACKER ETAL 2, 95,248

CENTRIFUGAL SWITCH Filed Sept. 29, 1943 2 Sheets-Sheet 1 Feb. 19, 1946.

J. W. BUSACKER ETAL CEN'TRIFUGAL SWITCH Filed Sept. 29, 1943 2 Sheets-Sheet 2 fag-M1 Patented Feb. 19, 1946 CENTRIFUGAL SWITCH John W. Busacker, Houston, Tex, and Joseph A. Tercsi, Pittsburgh, Pa., assignors to the United States of America, as represented by the Secrotary cf the Navy Application September 29, 1943, Serial No. 50, 1,288

6 Claims.

This invention relates to an improved centrifugal switch.

One object of the invention is to provide a centrifugal switch which will be operative for controlling a number of electric circuits within a radio proximity fuze system.

Another object of the invention is to provide a device of this character wherein provision is made for preventing premature closing of any of the circuits controlled.

Still further objects of the invention will suggest themselves as the description proceeds.

In the drawings:

Figure 1 shows the wiring diagram of a preferred form of the system in its approximate location within the nose of a projectile.

Figure 2 is a top plan view showing one embodiment of the invention.

Figure 3 is an enlarged detail sectional view showing the spring contact construction,

Figure 4 is a top plan view of the same embodiment with the switch elements in closed positions,

Figure 5 is a sectional view taken at 5-5 of Figure 4, and

Figure 6 is a top plan view showing a modified embodiment.

Referring first to Figure 2, the numeral l indicates generally a body which is of such size and shape that it may be fitted in a can of a radio proximity fuze. The body I is provided with a diametrally disposed chamber 2 and intersecting said chamber at right angles thereto is a radially extending chamber 3. Mounted in the opposite ends of the chamber 2 and in the outer end of the chamber 3 are contact jaws i. The jaws 4 are shown in detail in Figure 3 and, by referring to this view, it will be seen that said jaws include an upper spring contact element 5 and a lower spring contact element 5. The contact 5 of each jaw is connected with one portion of an electric circuit while the contact 6 is connected with another portion of the same circuit. The contact elements 5 extend inwardly of the chamber 2 or 3 so that the inner end thereof is disposed substantially in advance of the inner end of the element 6. Moreover, the inner end portion of the element 5 is bowed downwardly. The contact element 6 includes an inclined re-entrant portion 7 which cooperates with the bowed portion of the element 5 for firmly grasping the contact weight to be described hereinafter.

Contact weights 8 are arranged for sliding movement in the chamber 2 and one of said weights is also arranged for sliding movement in the chamber 3. Typical weights 8 are shown in Figure 3, and by referring to this view it will be seen that. said weights include a shank 9 and 2. lug It). The lugs IE! on the weights are arranged at different heights so that they will overlie. Said lugs are, moreover, provided with apertures which are normally aligned to receive a set back detent ll. Said detent being mounted axially of the body and being. normally pressed upwardly by a spring l2.

The operation of this embodiment of the invention will now be briefly described. The set back detent II will normally maintain the weights in their safe position out of engagement with the jaws 4. However, when a projectile containing the device is fired, the set back detent will be shifted downwardly for freeingthe weights and, by the action of centrifugal force due to the rotation of the projectile, said weights will be driven outwardly and into engagement with the jaws for bridging said jaws and closing the electric circuits.

It is desired to call particular attention to the fact that the bowed portions of the contact elements 5 of the jaws will serve to prevent the contact weights from accidentally contacting the lower element 6 and closing the circuits in the event that the set back detent should be displaced prematurely. That is to say, the bowed portion of the elements 5 will hold the contact weights in safe position against any forces of a smaller magnitude than the centrifugal forces.

The embodiment shown in Figure 6 will now be briefly described. This embodiment comprises a body I3 on which are arranged jaws l4, l5 and I6, said jaws being disposed at spaced points about the body. Pivotally mounted on the body are weighted contact members [1, said members having their corresponding inner ends aligned 40 against accidental displacement by a set back detent l8. Springs [9, which are arranged about the pivots, also urge the member Il' toward safe position.

In operation, however, when the set back de- 45 tent I8 is shifted downwardly, the members I! are swung outwardly to the position shown in dotted lines for closing the electric circuits controlled by said jaws.

It is thought that the construction and oper- 50 ation of the invention will now be understood.

What is claimed is:

1. In a centrifugal switch, a body having a chamber, a jaw carried in one end of the chamber, a contact weight carried in the chamber, and

55 set back releasable means carried by the body in the chamber to engage with the contact weight for normally retaining said weight in safe position, said set back retaining means being releasable by inertia upon firing of a projectile in which the switch is mounted for freeing the weight, and

said weight being movable by centrifugal force for engaging the jaws and closing an electric circuit, said jaw having a bowed contact member extending'in advance of its associated contact member for preventing movement of the contact weight into circuit closing position by any force weaker than the centrifugal force.

2. In a projectile, a centrifugal switch for a proximity fuze system having a body with one or,

more eccentrically pivotally mounted Weighted arms thereon swingable in a plane normal to the projectile axis, said arms being normally resiliently held againststops and retained in said 7 position by a detent, said detent being releasable by inertia upon firing of the projectile, and contact jaws for each of said arms, said arms, upon being released by the detent, flying outwardly due to' the centrifugal force as a result of the rotation of the projectile to engage their respective jaws for completing respective circuits in the proximity fuze system.

3. In an inertia switch for use in a rotating projectile, the combination with a supporting body having an axially mounted detent retractible under setback, and a plurality of contacts fixed and spaced about the detent, of a plurality of complementary contacts movable under centrifugal force and having their inner ends separably connected with the retractible detent.

4. In an inertia switch for use in a rotatin projectile with a guide body having a plurality of fixed contacts spaced about it axial center, and radially disposed complementary weights forming contacts movable under" centrifugal force, of an axially alined detent retractible under setback, and means separably connecting the weights with said detent.

5. In an inertia switch for use in a rotating projectile, the combination with a supporting guide body having an axially mounted detent retractible under setback, and a fixed contact spaced from itsfaxial center, of a weight forming 

